Not only has NASA’s New Horizons mission confirmed that Pluto has an extended atmosphere, after its historic flyby on July 14, the spacecraft observed a “cavity” in the solar wind, revealing a long plasma tail reminiscent of a comet’s ion tail.

Scientists have found gigantic sinkholes more than 200 yards (183 meters) in diameter -- twice the length of a football field -- and just about as deep breaking the surface of the comet being studied by the orbiting Rosetta spacecraft.